The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Mar. 26, 2019

Filed:

Dec. 16, 2016
Applicant:

Hitachi Metals, Ltd., Tokyo, JP;

Inventors:

Teppei Satoh, Mishima-gun, JP;

Futoshi Kuniyoshi, Mishima-gun, JP;

Rintaro Ishii, Mishima-gun, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B22F 3/00 (2006.01); B22F 3/24 (2006.01); C21D 6/00 (2006.01); C22C 38/00 (2006.01); H01F 1/057 (2006.01); H01F 41/02 (2006.01);
U.S. Cl.
CPC ...
H01F 1/0577 (2013.01); B22F 3/00 (2013.01); B22F 3/24 (2013.01); C21D 6/00 (2013.01); C21D 6/007 (2013.01); C22C 38/00 (2013.01); H01F 1/057 (2013.01); H01F 41/02 (2013.01); H01F 41/0293 (2013.01); B22F 2003/248 (2013.01); C22C 38/005 (2013.01);
Abstract

A method for manufacturing an R-T-B based sintered magnet includes: 1) a step of preparing an R-T-B based sintered magnet material by sintering a molded body at a temperature of 1,000° C. or higher and 1,100° C. or lower, and then performing (a) temperature dropping to 500° C. at 10° C./min or less, or (b) temperature dropping to 500° C. at 10° C./min or less after performing a first heat treatment of holding at a first heat treatment temperature of 800° C. or higher and 950° C. or lower, the R-T-B based sintered magnet material satisfying compositional requirements; and 2) a heat treatment step of performing a second heat treatment by heating the R-T-B based sintered magnet material to a second heat treatment temperature of 650° C. or higher and 750° C. or lower, and then cooling the R-T-B based sintered magnet material to 400° C. at 5° C./min or more.


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